Comment 31 for bug 1652348

The more I look at this, the more I'm convinced *most* of the real problem lies in that ipconfig tool. Yes, various kernel changes seem to make it alter between working & not working under the circumstances (which is bizarre), but unless something is specifically interfering with the inter-process communication, ipconfig appears to be ignoring valid dhcp responses, just based on whether you tell it "all" interfaces vs telling it a specific interface.

A small modification could be made to the initramfs-tools to have it iterate over the interfaces in the system one-at-a-time. It would marginally slow down the boot should the relevant interface not be the first, but it would get rid of this bug entirely. Or the intird environment could be modified to use dhclient instead of ipconfig (dhclient appears to be in the initrd, and works perfectly fine when called in a generic fashion, though the other initramfs-tools scripts seem aware ipconfig didn't complete successfully which I haven't looked in to)